Stabilization of peroxide solutions



Patented Aug. 27, 1935 2,012,462 STABILIZATION or 'rnnoxmn SOLUTIONS Carl Alexander Agthe, Zurich, and RudoltBlaser, Basel, Switzerland, assignors to the firm of J. R.

Geigy A. G., Basel, Switzerland No Drawing. Application June 8, 1933, Serial No. 674,946. In Germany June 22, 1932 '1 Claims. (Cl. 2s--251) Bleaching baths which contain 'a peroxide as the bleaching agent generally decompose far too quickly, so that the active, oxygen is lost without being utilized. Attempts to stabilize such baths The following examples illustrate the effect attained with preparations in accordance with the invention:

have thereforenotfbeenjlaking; and it has been E l8 1 found that a certain degree of stabilization can i i mg some chemical, sub 2 grams of sodium perborate are dissolved in Thus for m d m a (water glass) 150 com. of distilled water and the solution is and odium have largely been u'sed brought to the pH-Value 9.4 of hydro" for this purpose. On the other hand organic compounds, such as are described in German specifications No. 321,616, (salicylic acid), No. 318,220 (aniline); No. 318,134 and No. 242,324 have scarcly'foundapplication in the bleaching industry; for their use always involves the danger that, in so far as they are used alone and in relatively large proportions, they may become oxidized to compounds which have dyeing properchloric acid. 1 gram of the stabilizer is dissolved in the solution, the solution is heated to 95 C. and the decrease in the content of active oxygen in the course of time is determined. The results are shown in the following table in which are compared the actions of a mixture in accordance with the invention and the ingredients of the mixture used separately:--

ties and whose presence in a bleaching bath is '20 undesired. They have also the disadvantage that Active 0, their stabilizing action is good only in a neutral 7 bath; as the alkalinity of the bath increases they lose their stabilizing action, indeed much more Stabhw quickly than do the best of the known stabilizers, Initially namely sodium silicate and sodium pyrophos- 541m" 1110! 2mm phate.

According to the present invention agents hav- Per cent Per cent Per cent Per cent ing a very good stabilizing action on peroxide Sfiiflfi g gggg ggfggg f f; Q 3:2

solutions are obtained by mixing in suitable pro- Sodium pyrophosphate portion a salt of pyrophosphoric acid and a sulgtggg g glg gg phonic acid or carboxylic acid of an amine of the portion 100 87 14 an aromatic series or a salt thereof. Such agents are added to the bleaching bath in determined quantities according to the degree of stabilization Example 2 desired.

The aCtlOn attainedwi-thsuch a mixture iS not The solution consists of 150 com, of distilled additive, but surprisingly is much better than the water, 12 f hydrogen peroxide of 30 per sum of the actions of theingre'dients;.moreover cent strength, L6 f normal caustic soda 40 they stabilize well baths which are strongly alkasolution and 05 gram f Stabilizen line and have the further important advantage that they possess a good anti-catalytic action against the destructive influence of metals on the Active bleaching liq'uors.

,Of particular importance is the behaviour ,0 Stabilizer Amer the alkalineearth salts of the amino-sulphonic and amino-carboxylic acids which come into many 1 h 3 h question 'for the production of the stabilizing agents, particularly the barium salts. In admix- 0 ture with pyrophosphates they have a, stabilizing fgf, g; "2

action which in weakly alkaline solutions is about Sodium l:4-acetY as good as, and in strongly alkaline solutions is ;;;;lg;;;;g;,;;

appreciably superior to, that of the corresponding proportion 8B 72 58 sodium salts. 55

Example 3 The solution consists of 150 ccm. of conductivity water, 1.2 ccm. of normal caustic soda solution, 1.2 com. 01 hydrogen peroxide oi. 30 per cent strength and 0.5 gram of stabilizer.

(In each case 9 parts by weight of the pyrophosphate are mixed with 1 part by weight of the sulphonate.)

Example 4 The solution consists of 150 com. of distilled water, 1.6 com. or normal caustic soda solution, 1.6 com. of hydrogen peroxide 0! 30 per cent strength and 1 gram of stabilizer.

Active 0] Stabilizer ter Initially 3 hours 7 hours Per cent Per cent Per cent Neutrsliud sodium pyrophosphste. 83. 9 66. 0

Mixed with sodium meta-aminobemoate 100 89. 2 77. 3 Mixed with sodium ortho'aminobenzoaie 1(1) 86. 3 73. 5 Mixed with sodium 2:6-aminonaphthalene-suiphonaie 100 86. 3 73. 6

. (The sodium pyrophosphate and the amino-carboxylic acid or amino-sulphonic acid salt are in each case mixed in the proportion of 10: 1.)

Example 5 The solution consists of com. of distilled water, 1.4 ccm. of normal caustic soda solution, 1.2 com. of hydrogen peroxide of 30 per cent strength, 0.5 gram of stabilizer and 0.0015 gram of copper sulphate.

Active 0] Stabiliaar Alter Initially 5 hour 1% hours Per cent Per cent Per cent Neutralized sodium pyrophosphate 100 49 20 Mixed with sodium sulphenilate in the proportion 10:1 100 92 66 Example 6 The solution consists of 150 ccm. of distilled water, 5 ccm. of normal caustic soda solution, 1.2

ccm. of hydrogen peroxide of 30 per cent strength and 1 gram or stabilizer.

Act!" 0 Stabilizer Alter Initially K hour 3 hour Per cent Per cent Per cent Neutralized sodium pyrophosphate mixed with sodium sulphamlate- 100 58 16 Neutralized sodium pyro hosphate mixed with barium su phanilste in the proportion 10:1 it!) 72 a 34 What we claim is: 1. A process of stabilizing peroxide solutions,

consisting in mixing the solution at temperatures close to 95 C. with a salt of pyrophosphoric acid aromatic serial and a substituted amine oi the of the general formula N-Ar-R wherein X and Y represent hydrogen, an alhl or.

aralkyl radical, Ar represents a radical oithe benzene or naphthalene series, and R represents a solubilizing radical having hydrogen, an alkaline or alkaline-earth metal as cation.

2. A process of stabilizing peroxide solutions, consisting in mixing the solution at temperatures close to 95 C. with a salt of pyrophosphoric acid and a substituted amine of the aromatic series of the general formula N- om.

wherein X and Y represent hydrogen, an alkyl or aralkyl radical, and Ar represents a radical of the benzene or naphthalene series, Me being a cation such as hydrogen, an alkaline or alkaline-earth metal radical.

-3. A process of stabilizing peroxide solutions, consisting in mixing the solution at temperatures close to 95 C. with a. salt of pyrophosphoric acid and a substituted amine of the aromatic series of the general formula /N-Ar-SOsH Y wherein X and Y represent hydrogen, an alkyl or aralkyl radical, and Ar represents a radical of the benzene or naphthalene series.

4. A process of stabilizing peroxide solutions, consisting in mixing the solution at temperatures close to 95 C. with a salt of pyrophosphoric acid and a substituted amine of the aromatic series of the general formula \N-AI-SO1NB Y/ wherein X and Y represent hydrogen, an alkyl or aralkyl radical, and Ar represents a radical of the benzene or naphthalene series.

5. A process ofstabilizing peroxide solutions,

consisting in mixing the solution at temperatures close to 95 C. with a salt of pyrophosphoric acid and a substituted amine of the of the general formula aromatic series vwherein x and Y represent hydrogen, an albl or aralkyl radical, and Ar represents a radical of the benzene or naphthalene series.

6. A preparation for stabilizing peroxide solutions, consisting of a mixture of a salt 0! pyrophosphoric acid with a substituted mine of the aromatic series of the general formula wherein x and Y represent hydrogen, an alkyl or arallwl radical, Ar represents a radical of the benzene or naphthalene series, and R represents a solubilizing radical having hydrogen, an alkaline or alkaline-earth metal as cation.

7. A preparation for stabilizing peroxide solutions. consisting of a mixture of a salt of pyrophosphoric acid with a substituted amine of the aromatic series of the general formula wherein x and Y represent hydrogen, an alkyl or aralkyl radical, and Ar represents a radical of the benzene or naphthalene series, Me being a cation such as hydrogen, an alkaline or alkaline-earth metal.

CARL ALEXANDER AGTHE. RUDOLF BLASER. 

